A mere 7 percent of journalists identify as Republicans, and when they do give money to political campaigns they usually donate to Democrats, lending evidence to Republican presidential candidates’ claims that they are facing a hostile audience when they deal with the press.

As Republican candidates prepare for their fourth debate of the primary season Tuesday in Milwaukee, the people doing the questioning are increasingly in the spotlight, with their motives being questioned by the campaigns, voters and even by their fellow journalists.

And self-proclaimed Democratic journalists outnumber Republicans by 4-to-1, according to research by Lars Willnat and David Weaver, professors of journalism at Indiana University. They found 28 percent of journalists call themselves Democrats, while just 7 percent call themselves Republicans — though both numbers are down from the 1970s. Those identifying as independent have grown.

Among Washington correspondents, the ones who dominate national political coverage, it’s even more skewed, said Tim Groseclose, author of “Left Turn: How Liberal Media Bias Distorts the American Mind.” More than 90 percent of D.C. journalists vote Democratic, with an even higher number giving to Democrats or liberal-leaning political action committees, the author said.

“There’s something in the DNA of liberals that makes them want to go into jobs like the arts, journalism and academia more so than conservatives,” Mr. Groseclose said. “Even if you’re just trying to maximize profits by offering an alternative point of view, it’s hard to find conservative reporters. So it’s natural the media is more liberal.”

The bias factor has become front-page news after last month’s GOP presidential debate, which aired on CNBC, and which has drawn consistently bad reviews for how the moderators handled the questioning.

John Harwood, a CNBC and New York Times reporter who has written pieces on why Republicans are bad for the economy, asked front-runner Donald Trump if his run “was a comic book version of a presidential campaign.” Mr. Harwood later demanded that former Arkansas Gov. Mike Huckabee, a Baptist minister, say whether he believed Mr. Trump had “the moral authority” to be president. Mr. Huckabee didn’t take the bait.

“The Democrats have the ultimate super PAC — it is called the mainstream media,” U.S. Sen. Marco Rubio, one of the candidates on the stage, said to strong applause from the partisan Republican audience.

The debate was so widely panned that Republican National Committee Chairman Reince Priebus suspended future debates with NBC, and officials from different GOP campaigns are negotiating new restrictions on future affairs — to kick in after Tuesday’s debate.

That debate, airing on Fox Business Network, will have a slimmed-down field compared to the previous three debates. Just eight candidates polled well enough to make the main stage, with Mr. Huckabee and New Jersey Gov. Chris Christie relegated to the undercard. Meanwhile, two candidates who were in the previous undercard debates have been ousted — South Carolina Sen. Lindsey Graham and former New York Gov. George Pataki.

Fox Business Network anchors Maria Bartiromo and Neil Cavuto will moderate the main debate, along with Wall Street Journal editor in chief Gerard Baker.

Evening out?

David D’Alessio, a communications sciences professor at the University of Connecticut at Stamford, said there is bias in the press, but his research shows it evens out.

“If you stop to think about media as larger than just reporters and owners they’re business entities and their job is to make money. If you look at where people’s opinions are, they are in the middle, so that’s where a lot of reporting goes because that’s where the eyeballs go,” he said.

Mr. D’Alessio argues that for every liberal news network like MSNBC, there’s a Fox News counterpoint because the market creates that opening. For The Huffington Post online, there’s the Drudge Report online, and for The New York Times there’s the New York Post.

But overall, he says, the mainstream media tend to be more neutral in their tone despite an individual reporter’s ideological preferences, because they want to appeal to both conservative and liberal viewers alike — because that’s where the greatest market is for making money. People only perceive the mainstream media as being biased because of their own biases.

“If a person is ideological, the more closely they’re going to zero in on things they disagree with,” Mr. D’Alessio said.

He conducted an experiment where he gave the same newspaper article to both Republicans and Democrats and told them to circle the bias. Republicans circled the liberal viewpoint in the story whereas the Democrats circled the conservative representation.

“But both sides were represented,” he said. “People need to take a step back and evaluate [that] just because I don’t agree with what someone says in the newspaper doesn’t mean the newspaper is lying about it.”

Mr. Groseclose, an economics professor at George Mason University, said his research does find a tilt even in what he classifies as mainstream press, including publications such as The New York Times and The Washington Post and the major broadcast networks — but excluding Fox News and others that have an obvious ideological bent.

But it’s not as much as some conservatives decry.

In his study Mr. Groseclose measured the mainstream press on a 0-to-100 point scale, with 100 being the most liberal, like a speech from Democratic House Speaker Nancy Pelosi, and 50 being centrist. The media tended to come in at 60 — still not neutral, but not so slanted as some conservatives claim.

There’s evidence that bias matters.

People’s voting patterns are influenced by which kind of media they follow, according to a study done by Alan Gerber, a political science professor at Yale University. Mr. Gerber offered people in the Washington metropolitan area a free subscription to either The Washington Post or The Washington Times for several weeks ahead of a gubernatorial election. The Post, by his estimation and work done before, slanted as much to the left as The Times did to the right.

In a survey he conducted after the election, Mr. Gerber found those who were given a free subscription of The Post were 8 percentage points more likely to vote for the Democratic candidate for governor than those assigned to the control group.

This article was originally posted at the WashingtonTimes.com website.